The present invention relates to a data processing system, a data processing method, an information processing device, and a computer program. More particularly, the present invention relates to a data processing system, a data processing method, an information processing device, and a computer program, which achieve better data retrieval efficiency on a peer-to-peer network.
Recently, images, audio data, various programs, and the like have been increasingly transferred over a communication network such as the Internet. Content exchanged over a network has changed from mono-media content including text and still images to multimedia content including moving pictures and audio. The volume of such multimedia content has tremendously increased.
Meanwhile, in recent years, peer-to-peer (P2P) network technology has been developed as a direct communication processing scheme between information processing devices. In the P2P network scheme, instead of using a server for performing intensive processing, information processing devices or resources owned by network clients, including personal computers (PCs), portable terminals, PDAs (personal digital assistants), cellular telephones, and other devices having the communication capability or connected to a communication device, such as disc devices serving as storage units and printers, communicate with each other over a network to share the resources of the network clients.
The P2P network technology is said to be first introduced in APPN (Advanced Peer-to-Peer Networking) proposed by International Business Machines Corporation. This network scheme eliminates necessity for a single giant delivery server which is required for content delivery in a traditional client-server network, while allowing content distributed in resources owned by network clients to be shared by a large number of users, thereby discretely storing and delivering a large volume of content.
Two types of peer-to-peer (P2P) networks are known, i.e., a pure peer-to-peer (P2P) network and a hybrid peer-to-peer (P2P) network. FIGS. 1A and 1B illustrate the pure P2P network and the hybrid P2P network, respectively. In the pure P2P network, system nodes (peer devices) having an equal function and role communicate with each other in a peer-to-peer fashion. A typical service using the pure P2P network is Gnutella (http://gnutella.wego.com/). In the hybrid P2P network, a control server for providing smooth interaction between system nodes (peer devices) is further provided for the pure P2P network. A typical service using the hybrid P2P network is Napster® (http://www.napster.com/).
However, these traditional P2P networks have suffered from the following problems in order to retrieve desired content:
1. the pure P2P network does not include a database for managing content and users, leading to an increased amount of traffic when desired content is retrieved, and it may therefore be difficult to retrieve the desired content; and
2. the hybrid P2P network requires a database for managing a correspondence between content and a system node (peer device) having the content, resulting in a high load on a managing server.